Radio equipment



Sept. 11, 1928. 1,683,748

A. E; WHITE Y RADIO EQUIPMENT Filed Jan. 28, 4926 W IQVENTOR' I 25 a stan ard phone plug bear Patented Sept. 11, 1928.

PATENT OFFICE.

m' W HITE, O1 PASADENA, CALIFORNIA;

name neurrmnnr.

Application Med January 28, 1926. Serial 1T0. 84,550.

The invention relates to means of any and all radio equipment including that for. transmitting and receivin filaments of the tubes may be eated either 6 by alternating or direct current whereby as applied to receivers eliminates the great expense of dry cells for this purpose or-the. expense andconstant care of a charger and special storage battery beiiuseaimo'st every 10 user is already provided with alternating current for 1i hting his residence and a storage battery in his automobile, and wherewith in connection with my means of. filament supply reliable and economic operation is provided both for home and motor camping service.

I accomplish this as shown in the accom- "panyin drawing. As no plugs are shown inserte in the jacks J and J 2 the set is now 2 indicated as operating its speaker, 12 with the tube filaments heated from 110 volt AC service using the transformer 9, but if it is inconvenient to use this service or if very clear si als are desired for use of ear phones,

' DC current may be inserted in the jack J w 'ch will automatically and accurately perform all necessary changes in the connections for the set to properly use the DC filament supply. Now

' returning to the operationof t e set with the AC supply it is to be noted that on jack J the s ring-blade 2 is making contact: with 3 and e spring-blade 5 is makin contact with 4 thus puttmg the voltage of t e trans former 9 onto the tube filaments and the grid return of f the first-audio transformer 14 through the C battery 7. Now let us changf tothe DC filament supply by inserting t e above-mentioned phone plug beerso that the ing the DC voltage into the jack J and it will benoted that this insertion will auto-' ments withcorrect polarity through the frame .-1 and spring-blade 2 of this jack less any desired loss in voltage by the separation of 1 from 6 on the resistance 8 The insertion of this plug also separates 4 from 5 and connects 5 with 1 through the sleeveof the plug thus now making the grid return 5 of Y the audio transformer 14 .to the negative filament wire. It is understood that this plan can also be used in other circuits and equipment than the simple one here illustrated and considering the foregoing that which I claim to have invented is:

In a radio receiving circuit comprising one or more vacuum tubes having filamentsadapted to be energized from either an alternating or a direct current source and grid electrodes, means for applying alternating current to said filaments comprising a trans former the secondary of which is shunted by a potentiometer, means for connecting sa d grid electrodes to a point on said potentiometer, a. multi-contact jack connected between the filaments and the transformer, a plug adapted to be inserted in said jack connects to a direct current sourcefor opening the circuit between the filaments and the transformer and for connecting the id electrodes to the negative pole of the t current source when the is inserted in the jack.

ALFRED ERNEST WHITE. 

